Sanders picks up more superdelegates

Sen. Bernie Sanders picked up another superdelegate on Thursday: New Hampshire Democratic Party vice chairwoman Martha Fuller Clark, who also serves as a state senator.

Clark's backing on Thursday, confirmed by the Sanders campaign, is the latest in a string of superdelegate endorsements Sanders has gained in the past week.

On Thursday afternoon Maureen Monahan, vice chair of the Nebraska Democratic Party, announced that she would back Sanders and encouraged other unpledged superdelegates to support him.

"In the primaries and caucuses held so far, Senator Sanders has won about 45% of the pledged delegates, yet has pledges from only about 6% of the “super delegates.” No wonder Sanders voters are so frustrated with the party," Monahan said in a statement. "Party leaders need to acknowledge and embrace Senator Sanders and his supporters. That is why today I am pledging my super delegate vote to Senator Sanders. I am encouraging all still unpledged super delegates to support Senator Sanders as well. We need new energetic people in the Democratic Party to spread our effective message."

On Tuesday, Hawaii's Democratic Party elected Tim Vandeveer as its party chairman, meaning he also becomes a superdelegate. Vandeveer said he would vote for Sanders at the state party convention. A week earlier, West Virginia Democratic National Committeewoman Elaine Harris said she would support Sanders in her role as a superdelegate.

That newfound support for Sanders doesn't ease the steep uphill climb he faces to catch up to former Secretary of State Hillary Clinton. Sanders, according to The Associated Press delegate tracker, has just 44 superdelegates, while Clinton has 543.